Develop Reference

WPF Custom control binding image source

I have a custom control based on a button, and I put an image inside. I can set the source of the image in the xaml, but if I try and bind it, it doesn't work.
Generic.xaml
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:CustomControl">
<Style TargetType="{x:Type local:MyCustomControl}" BasedOn = "{StaticResource {x:Type Button}}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:MyCustomControl}">
<Grid x:Name="InnerGrid">
<Image Source="pathname"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
This works just fine, however if I replace the <Image Source="pathname"/> with <Image Source={Binding MyImage, RelativeSource={RelativeSource Self}}"/>, and reference a Delegate Property in the class, it breaks.
MyCustomControl.cs
public class MyCustomControl : Button
{
static DependencyProperty m_myimage = null;
private DependencyProperty MyImageProperty
{
get
{
return m_myimage;
}
}
public BitmapImage MyImage
{
get
{
return (BitmapImage)GetValue(MyImageProperty);
}
set
{
SetValue(MyImageProperty, value);
}
}
protected override void OnInitialized(EventArgs e)
{
base.OnInitialized(e);
MyImage = new BitmapImage(new Uri(pathname));
}
private static void RegisterDependencyProperties()
{
if (m_myimage == null)
{
m_myimage = DependencyProperty.Register("MyImage",
typeof(BitmapImage), typeof(MyCustomControl), null);
}
}
static MyCustomControl()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(MyCustomControl),
new FrameworkPropertyMetadata(typeof(MyCustomControl)));
RegisterDependencyProperties();
}
}
How can I get it to work?

Figured it out myself after about 2 hours. The xaml binding should look like,
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:MyCustomControl}">
<Grid x:Name="InnerGrid">
<Image Source="{Binding MyImage, RelativeSource={RelativeSource TemplatedParent}}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
Note that the binding relative resource went from RelativeSource={RelativeSource Self} to RelativeSource={RelativeSource TemplatedParent}

How to draw grid lines that scale?

I have a canvas, and I want to give it grid lines as a background, but I want there to be a constant number of grid lines that divide the canvas into equally-sized sections, rather than just have equally-spaced grid-lines. I want this to be preserved when the canvas is resized by the user.
How should I do this?

Here is a solution which is based in two wpf ListView controls behind the canvas(one for rows and second for columns). The content of the columns related ListView control is a rectangle.
Updated version - Managed Grid Lines Control. Here you can manage the number of grid lines and their visibility.
Xaml code - grid lines control:
<UserControl x:Class="CAnvasWithGrid.GridLineControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:canvasWithGrid="clr-namespace:CAnvasWithGrid"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300" x:Name="This">
<Grid x:Name="LayoutRoot">
<Grid.Resources>
<Style TargetType="ListView">
<Setter Property="Background" Value="Transparent"/>
</Style>
<Style x:Key="ListViewItemStyle" TargetType="ListViewItem">
<Setter Property="Background" Value="Transparent"/>
</Style>
<DataTemplate x:Key="InnerListviewDataTemplate" DataType="{x:Type canvasWithGrid:CellModel}">
<Rectangle HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
Margin="0" StrokeDashArray="4" Stroke="Black" StrokeThickness="0.5" Fill="Transparent"/>
</DataTemplate>
<DataTemplate x:Key="ListviewDataTemplate" DataType="{x:Type canvasWithGrid:RowModel}">
<ListView ItemsSource="{Binding CellModels}" BorderBrush="#00FFFFFF" BorderThickness="0" Margin="0"
HorizontalContentAlignment="Stretch"
VerticalContentAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalAlignment="Stretch" ScrollViewer.HorizontalScrollBarVisibility="Hidden" ScrollViewer.VerticalScrollBarVisibility="Hidden">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Columns="{Binding CellModels, Converter={canvasWithGrid:CollectionLength2NumberConverter}}"></UniformGrid>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem" BasedOn="{StaticResource ListViewItemStyle}">
<Setter Property="Margin" Value="0"></Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<ContentPresenter Content="{TemplateBinding Content}" Margin="0"
ContentTemplate="{StaticResource InnerListviewDataTemplate}" />
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="ContentTemplate" Value="{StaticResource InnerListviewDataTemplate}"/>
</Style>
</ListView.ItemContainerStyle>
</ListView>
</DataTemplate>
</Grid.Resources>
<ListView ItemsSource="{Binding ElementName=This, Path=RowModels}" ScrollViewer.HorizontalScrollBarVisibility="Hidden" ScrollViewer.VerticalScrollBarVisibility="Hidden">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Rows="{Binding ElementName=This, Path=RowModels, Converter={canvasWithGrid:CollectionLength2NumberConverter}}"/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem" BasedOn="{StaticResource ListViewItemStyle}">
<Setter Property="Margin" Value="0"></Setter>
<Setter Property="HorizontalAlignment" Value="Stretch"/>
<Setter Property="VerticalAlignment" Value="Stretch"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Stretch"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<ContentPresenter Content="{TemplateBinding Content}" Margin="-1"
ContentTemplate="{StaticResource ListviewDataTemplate}" />
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="ContentTemplate" Value="{StaticResource ListviewDataTemplate}"/>
</Style>
</ListView.ItemContainerStyle>
</ListView>
</Grid>
Grid lines control - code behind
/// <summary>
/// Interaction logic for GridLineControl.xaml
/// </summary>
public partial class GridLineControl : UserControl
{
public GridLineControl()
{
InitializeComponent();
}
public static readonly DependencyProperty NumberOfColumnsProperty = DependencyProperty.Register(
"NumberOfColumns", typeof (int), typeof (GridLineControl), new PropertyMetadata(default(int), NumberOfColumnsChangedCallback));
private static void NumberOfColumnsChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
var numberOfRows = (int)dependencyObject.GetValue(NumberOfRowsProperty);
var numberOfColumns = (int)args.NewValue;
if (numberOfColumns == 0 || numberOfRows == 0) return;
var rowModelsCollection = GetRowModelsCollection(numberOfRows, numberOfColumns);
dependencyObject.SetValue(RowModelsProperty, rowModelsCollection);
}
public int NumberOfColumns
{
get { return (int) GetValue(NumberOfColumnsProperty); }
set { SetValue(NumberOfColumnsProperty, value); }
}
public static readonly DependencyProperty NumberOfRowsProperty = DependencyProperty.Register(
"NumberOfRows", typeof (int), typeof (GridLineControl), new PropertyMetadata(default(int), NumberOfRowsChangedCallback));
private static void NumberOfRowsChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
var numberOfRows = (int)args.NewValue;
var numberOfColumns = (int)dependencyObject.GetValue(NumberOfColumnsProperty);
if(numberOfColumns == 0 || numberOfRows == 0) return;
var rowModelsCollection = GetRowModelsCollection(numberOfRows, numberOfColumns);
dependencyObject.SetValue(RowModelsProperty, rowModelsCollection);
}
private static ObservableCollection<RowModel> GetRowModelsCollection(int numberOfRows, int numberOfColumns)
{
var rowModelsCollection = new ObservableCollection<RowModel>();
for (var i = 0; i < numberOfRows; i++)
{
rowModelsCollection.Add(new RowModel(numberOfColumns) {Position = (i + 1).ToString()});
}
return rowModelsCollection;
}
public int NumberOfRows
{
get { return (int) GetValue(NumberOfRowsProperty); }
set { SetValue(NumberOfRowsProperty, value); }
}
public static readonly DependencyProperty RowModelsProperty = DependencyProperty.Register("RowModels",
typeof(ObservableCollection<RowModel>), typeof(GridLineControl),
new PropertyMetadata(default(ObservableCollection<RowModel>)));
public ObservableCollection<RowModel> RowModels
{
get { return (ObservableCollection<RowModel>)GetValue(RowModelsProperty); }
private set { SetValue(RowModelsProperty, value); }
}
}
Models:
public class RowModel:BaseGridMember
{
public RowModel(int numberOfCellsInRow)
{
CellModels = new ObservableCollection<CellModel>();
for (int i = 0; i < numberOfCellsInRow; i++)
{
CellModels.Add(new CellModel{Position = (i+1).ToString()});
}
}
public ObservableCollection<CellModel> CellModels { get; set; }
}
public class CellModel:BaseGridMember
{
}
public class BaseGridMember:BaseObservableObject
{
private string _position;
public string Position
{
get { return _position; }
set
{
_position = value;
OnPropertyChanged();
}
}
}
Main window xaml code - as you can see here is a ImageContol instead of Canvas but you can replace it:
<Window x:Class="CAnvasWithGrid.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:canvasWithGrid="clr-namespace:CAnvasWithGrid"
Title="MainWindow" Height="525" Width="525" x:Name="This">
<Grid Tag="{Binding ElementName=This}">
<Grid.Resources>
<BooleanToVisibilityConverter x:Key="Bool2VisConvKey" />
</Grid.Resources>
<Grid.ContextMenu>
<ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Show Grid Lines" Command="{Binding ShowGridLinesCommand}"/>
</ContextMenu>
</Grid.ContextMenu>
<Image Source="Resources/Koala.jpg" Stretch="Uniform" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" MouseDown="UIElement_OnMouseDown"/>
<canvasWithGrid:GridLineControl NumberOfRows="50" NumberOfColumns="50"
IsHitTestVisible="False" Visibility="{Binding ElementName=This, Path=AreGridLineVisible, Converter={StaticResource Bool2VisConvKey}, UpdateSourceTrigger=PropertyChanged}"/>
</Grid>
Main window code behind:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
ShowGridLinesCommand = new RelayCommand(ShowGridLineManageCommand);
AreGridLineVisible = true;
}
private void ShowGridLineManageCommand()
{
AreGridLineVisible = !AreGridLineVisible;
}
public static readonly DependencyProperty AreGridLineVisibleProperty = DependencyProperty.Register(
"AreGridLineVisible", typeof (bool), typeof (MainWindow), new PropertyMetadata(default(bool)));
public bool AreGridLineVisible
{
get { return (bool) GetValue(AreGridLineVisibleProperty); }
set { SetValue(AreGridLineVisibleProperty, value); }
}
public static readonly DependencyProperty ShowGridLinesCommandProperty = DependencyProperty.Register(
"ShowGridLinesCommand", typeof (ICommand), typeof (MainWindow), new PropertyMetadata(default(ICommand)));
public ICommand ShowGridLinesCommand
{
get { return (ICommand) GetValue(ShowGridLinesCommandProperty); }
set { SetValue(ShowGridLinesCommandProperty, value); }
}
private void UIElement_OnMouseDown(object sender, MouseButtonEventArgs e)
{
}
}
How it looks like:

Sounds like a candidate for a custom control with custom drawing. You don't really want to use multiple FrameworkElements like "Line" if you are expecting many grid-lines for performance reasons.
So you'd create a customControl GridLinesControl and overwrite the OnRender method. You can get the actual width and height of the component using the properties ActualWidth and ActualHeight, divide by the number of grid lines you want and draw lines using drawingContext.DrawLine.
The easiest way would be to add the GridLinesControl you've made underneath the canvas, taking up the same space (so it has the right ActualWidth and ActualHeight) like this:
<Grid>
<myControls:GridLinesControl/>
<Canvas ... />
</Grid>
So it's always underneath.

WPF Custom Control - Button Event

I start the WPF today, I'm trying to implement a custom control.
My problem is that I can not select an element in the template.
My code:
[Generic.xaml]
<Style x:Key="{x:Type local:ImageButton}" TargetType="{x:Type local:ImageButton}" BasedOn="{StaticResource {x:Type Button}}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:ImageButton}">
<StackPanel>
// -> My image
<Image Source="{Binding Path=Tag, RelativeSource={RelativeSource TemplatedParent}}"></Image>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
[ImageButton.cs]
public class ImageButton : Button
{
public Image imageOff { get; set; }
public Image imageOn { get; set; }
static ImageButton()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(ImageButton), new FrameworkPropertyMetadata(typeof(ImageButton)));
}
public ImageButton()
: base()
{
this.MouseEnter += new MouseEventHandler(SetImageON);
}
public void SetImageON(object sender, MouseEventArgs e)
{
//Here i wanna change my image from StackPanel
}
}
Am I on the good way ? How can I change that image?

Give a name to your image, like x:Name="PART_Image". Then in your code behind override OnApplyTemplate method and store it into a variable.
private Image PART_Image;
public override void OnApplyTemplate()
{
PART_Image = this.GetTemplatedChild("PART_Image");
}
In this case you can access it in your method like:
this.PART_Image.Visibility = Visibility.Collapsed;

sender is your control so you could also right this.SetCurrentValue.
public void SetImageON(object sender, MouseEventArgs e)
{
ImageButton btn = (ImageButton)sender;
btn.SetCurrentValue(TagProperty,imageOn.Source);
}
it seems as though you might wan't to just save the source of your image in the control , instead of the entire image.
But if you wan't to use an Image object in code like this
xaml : in your template .
<StackPanel x:Name="myPanel" />
cs : in your control :
myPanel.Children.Add(imageOn);

You can achieve what you want with a Trigger:
<Style x:Key="{x:Type local:ImageButton}" TargetType="{x:Type local:ImageButton}" BasedOn="{StaticResource {x:Type Button}}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:ImageButton}">
<StackPanel>
<Image Source="{Binding Path=imageOff.Source, RelativeSource={RelativeSource TemplatedParent}}">
<Image.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Image.Source" Value="{Binding Path=imageOn.Source, RelativeSource={RelativeSource TemplatedParent}}" />
</Trigger>
</Image.Triggers>
</Image>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
That way you don't need the event in the code-behind. If you wanted to, you could make imageOff and imageOn DependencyProperties, that way you could define the source images in xaml too:
public class ImageButton : Button {
public static readonly DependencyProperty imageOffProperty = DependencyProperty.Register("imageOff", typeof(Image), typeof(ImageButton), new PropertyMetadata(null));
public Image imageOff {
get { return (Image)GetValue(imageOffProperty); }
set { SetValue(imageOffProperty, value); }
}
public static readonly DependencyProperty imageOnProperty = DependencyProperty.Register("imageOn", typeof(Image), typeof(ImageButton), new PropertyMetadata(null));
public Image imageOn {
get { return (Image)GetValue(imageOnProperty); }
set { SetValue(imageOnProperty, value); }
}
static ImageButton()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(ImageButton), new FrameworkPropertyMetadata(typeof(ImageButton)));
}
}
So when you declare an ImageButton in xaml, you can do something like this:
<local:ImageButton imageOn="/Resource/Path/To/imageOn.png" imageOff="/Resource/Path/To/imageOff.png" />

how to set some default text at the passwordBox wpf? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Watermark TextBox in WPF
May i know how to put some default texts in the password box in WPF?
I use MSN messenger as an example. When its default, the password field will show the "password" in the Password Box. When i click and type on the password box, the "password" text will disappear and the dots will replace it.

You have to create a custom control to do that.
XAML:
<Window x:Class="WpfTest.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:WpfTest="clr-namespace:WpfTest"
Title="Password Box Sample" Height="300" Width="300">
<Window.Resources>
<Style x:Key="{x:Type PasswordBox}"
TargetType="{x:Type PasswordBox}">
<Setter Property="WpfTest:PasswordBoxMonitor.IsMonitoring"
Value="True"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type PasswordBox}">
<Border Name="Bd"
Background="{TemplateBinding Background}"
BorderThickness="{TemplateBinding BorderThickness}"
BorderBrush="{TemplateBinding BorderBrush}"
SnapsToDevicePixels="true">
<Grid>
<ScrollViewer x:Name="PART_ContentHost"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
<TextBlock Text="Please enter your password"
Margin="4, 2, 0, 0"
Foreground="Gray"
Visibility="Collapsed"
Name="txtPrompt" />
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled"
Value="false">
<Setter TargetName="Bd"
Property="Background"
Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
<Trigger Property="WpfTest:PasswordBoxMonitor.PasswordLength" Value="0">
<Setter Property="Visibility" TargetName="txtPrompt" Value="Visible"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<PasswordBox VerticalAlignment="Top"/>
</Grid>
</Window>
C# code:
using System.Windows;
using System.Windows.Controls;
namespace WpfTest
{
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
}
public class PasswordBoxMonitor : DependencyObject
{
public static bool GetIsMonitoring(DependencyObject obj)
{
return (bool)obj.GetValue(IsMonitoringProperty);
}
public static void SetIsMonitoring(DependencyObject obj, bool value)
{
obj.SetValue(IsMonitoringProperty, value);
}
public static readonly DependencyProperty IsMonitoringProperty =
DependencyProperty.RegisterAttached("IsMonitoring", typeof(bool), typeof(PasswordBoxMonitor), new UIPropertyMetadata(false, OnIsMonitoringChanged));
public static int GetPasswordLength(DependencyObject obj)
{
return (int)obj.GetValue(PasswordLengthProperty);
}
public static void SetPasswordLength(DependencyObject obj, int value)
{
obj.SetValue(PasswordLengthProperty, value);
}
public static readonly DependencyProperty PasswordLengthProperty =
DependencyProperty.RegisterAttached("PasswordLength", typeof(int), typeof(PasswordBoxMonitor), new UIPropertyMetadata(0));
private static void OnIsMonitoringChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var pb = d as PasswordBox;
if (pb == null)
{
return;
}
if ((bool) e.NewValue)
{
pb.PasswordChanged += PasswordChanged;
}
else
{
pb.PasswordChanged -= PasswordChanged;
}
}
static void PasswordChanged(object sender, RoutedEventArgs e)
{
var pb = sender as PasswordBox;
if (pb == null)
{
return;
}
SetPasswordLength(pb, pb.Password.Length);
}
}
}
Reference: WPF Watermark PasswordBox from Watermark TextBox

Troubleshooting Binding Error 4

I'm getting the following Binding errors on my code and I don't know how to troubleshoot them. The bindings were generated by VS. I've tried adding presentation.tracesources (which is in the code below) but I get the same output as before.
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='ClimateSolutions.SuperTB', AncestorLevel='1''. BindingExpression:Path=myName; DataItem=null; target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='ClimateSolutions.SuperTB', AncestorLevel='1''. BindingExpression:Path=isRequired; DataItem=null; target element is 'SuperTB' (Name='email'); target property is 'NoTarget' (type 'Object')
Here's my XAML:
<TextBox x:Class="ClimateSolutions.SuperTB"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d" Height="53" Width="296" FontSize="32"
xmlns:local="clr-namespace:ClimateSolutions"
xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=WindowsBase"
HorizontalAlignment="Left" Name="Blarg">
<TextBox.Style>
<Style TargetType="TextBox">
<Style.Triggers>
<Trigger Property="Text" Value="">
<Setter Property="Background">
<Setter.Value>
<VisualBrush Stretch="None">
<VisualBrush.Visual>
<TextBlock Foreground="Gray" FontSize="24" Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:SuperTB, AncestorLevel=1}, Path=myName, diagnostics:PresentationTraceSources.TraceLevel=High}">
</TextBlock>
</VisualBrush.Visual>
</VisualBrush>
</Setter.Value>
</Setter>
</Trigger>
<DataTrigger Binding="{Binding Path=isRequired, RelativeSource={RelativeSource FindAncestor, AncestorType=local:SuperTB, AncestorLevel=1}}" Value="False">
<Setter Property="Text" Value="100" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
and here's the CS for SuperTB:
namespace ClimateSolutions
{
/// <summary>
/// Interaction logic for SuperTB.xaml
/// </summary>
public partial class SuperTB : TextBox, INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String Property)
{
var anEvent = this.PropertyChanged;
if (anEvent != null)
{
anEvent(this, new PropertyChangedEventArgs(Property));
}
}
private String MyName = "Unicorns!";
private static DependencyProperty myNameProperty = DependencyProperty.Register("myName", typeof(String), typeof(SuperTB));
public String myName
{
get { return MyName; }
set { MyName = value; NotifyPropertyChanged("myName"); }
}
DependencyProperty isRequiredProperty = DependencyProperty.Register("isRequired", typeof(Boolean), typeof(SuperTB));
public Boolean isRequired
{
get { return (Boolean)GetValue(isRequiredProperty); }
set { SetValue(isRequiredProperty, value); }
}
public SuperTB()
{
InitializeComponent();
myName = "Unicorns!";
}
}
}

EDIT : I have updated the code according to your comment. To summarize, since this is a custom control, you are less dependant on the MVVM pattern to build your component logic (and thus use code behind in you component) as soon as your componennt itself meets this needs (to be sort, make its properties to be as much bindable as you can). For example, in the updated code, you can now bind the default property, but you can also imagine exposing properties to set the foreground colors used to diaplay control name when there is no value, and so forth.
I tried several things with you original code (included solution provided by J cooper) and nothing seemed to work. It seems that there is a lot of issues with your code.
I managed to approach a solution by making your textbox a custom control.
Here is the Generic.xaml (the visual definition of your control) :
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Question_6514447">
<Style TargetType="{x:Type local:SuperTB2}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:SuperTB2}">
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<TextBox x:Name="PART_Input">
<TextBox.Style>
<Style TargetType="TextBox">
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsRequired}" Value="False">
<Setter Property="Text" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=DefaultTextValue}" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
And here is the code behind of the control :
[TemplatePart(Name = "PART_Input")]
public class SuperTB2 : Control
{
private TextBox PART_Input;
static SuperTB2()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(SuperTB2), new FrameworkPropertyMetadata(typeof(SuperTB2)));
}
public SuperTB2()
{
Loaded += SuperTb2Loaded;
}
public override void OnApplyTemplate()
{
PART_Input = GetTemplateChild("PART_Input") as TextBox;
if (PART_Input != null)
{
PART_Input.GotFocus += PartInputGotFocus;
PART_Input.LostFocus += PartInputLostFocus;
}
}
void PartInputLostFocus(object sender, RoutedEventArgs e)
{
if (PART_Input.Text == string.Empty)
{
PART_Input.Text = Name;
PART_Input.Foreground = new SolidColorBrush(Colors.Gray);
}
}
void PartInputGotFocus(object sender, RoutedEventArgs e)
{
if (PART_Input.Text.Equals(Name))
{
PART_Input.Text = string.Empty;
PART_Input.Foreground = new SolidColorBrush(Colors.Black);
}
}
void SuperTb2Loaded(object sender, RoutedEventArgs e)
{
if (PART_Input.Text == string.Empty)
{
PART_Input.Text = Name;
PART_Input.Foreground = new SolidColorBrush(Colors.Gray);
}
}
private static DependencyProperty myNameProperty =
DependencyProperty.Register("MyName", typeof(string), typeof(SuperTB2), new PropertyMetadata("Unicorns !", NameChanged));
private static void NameChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
}
public string MyName
{
get { return (string)GetValue(myNameProperty); }
set { SetValue(myNameProperty, value); }
}
DependencyProperty isRequiredProperty =
DependencyProperty.Register("IsRequired", typeof(bool), typeof(SuperTB2), new PropertyMetadata(false, IsReqChanged));
private static void IsReqChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
}
public bool IsRequired
{
get { return (bool)GetValue(isRequiredProperty); }
set { SetValue(isRequiredProperty, value); }
}
public string DefaultTextValue
{
get { return (string)GetValue(DefaultTextValueProperty); }
set { SetValue(DefaultTextValueProperty, value); }
}
// Using a DependencyProperty as the backing store for DefaultTextValue. This enables animation, styling, binding, etc...
public static readonly DependencyProperty DefaultTextValueProperty =
DependencyProperty.Register("DefaultTextValue", typeof(string), typeof(SuperTB2), new UIPropertyMetadata("100"));
}
And an example of use of the component :
<Grid>
<StackPanel>
<Question_6514447:SuperTB2 x:Name="FirstName" IsRequired="true" DefaultTextValue="200"/>
</StackPanel>
</Grid>
With this updated code, I think you can acheive almost all the behaviors your needed !
Hope this will help !

Do not use relative source in your binding expressions. Relative source is used to access elements higher in the element tree. It seems as though you were using it in terms of object inheritance.
<Trigger Property="Text" Value="">
<Setter Property="Background">
<Setter.Value>
<VisualBrush Stretch="None">
<VisualBrush.Visual>
<TextBlock Foreground="Gray" FontSize="24" Text="{Binding Path=myName, diagnostics:PresentationTraceSources.TraceLevel=High}">
</TextBlock>
</VisualBrush.Visual>
</VisualBrush>
</Setter.Value>
</Setter>
</Trigger>
<DataTrigger Binding="{Binding Path=isRequired}" Value="False">
<Setter Property="Text" Value="100" />
</DataTrigger>